In Vitro Cell Migration and Wound Closure Efficiency of Wound Gels Evaluated by a Monolayer Scratch Wound Model

Cell migration plays a key role in both normal physiological and pathological conditions, including wound healing. The in vitro scratch wound model is a commonly used model to assess cell migration and wound closure due to its simplicity, reproducibility, and cost-effectiveness. In this study, monolayer scratch wound models of human dermal fibroblast (HDFa), an immortal keratinocyte cell line (HaCaT), and mesenchymal stem cells (MSC) were created by scratching the cell monolayers with a sterile 100 µl pipette tip in six well cell culture plates.

After scratching, cells were washed using PBS to remove cell debris caused from the scratch. Each treatment solution was added to cells (2 ml/well) and included 0.5% (v/v) of a concentrated surfactant gel preserved with antimicrobials (CSG), a concentrated surfactant gel loaded with SSD (CSG-SSD), and a PHMB loaded gel (PXG). To ensure images were taken in the same place each time, three lines were drawn evenly on the underside of the dish, perpendicular to the scratch. Three images of the scratch area were taken using x10 magnification at the drawn lines for each sample at 0, 8, 24, and 48 hours. The scratch areas were measured by ImageJ for all the groups. Wound closure was determined as percentage closure (%), which was subsequently calculated as follows:

Wound closure = ((Scratch area at 0 hour-Uncovered scratch area)/(Scratch area at 0 hour))x100

The results implied that 0.5% CSG improved cell mobility and accelerated cell migration, especially with HDFa and HaCaT. It was impossible to distinguish the edge of the scratch after CSG-SSD treatment on HDFa due to a large number of cells detaching after the tip-scratch. This may be due to the SSD in the CSG decreasing extracellular protein secretion by HDFa, resulting in the cells detaching more readily following the scratch.